Environmental news from California and beyond

Big plans for geothermal energy

October 22, 2008 | 10:16
pm

Vast stretches of federal land in the West would be open to geothermal energy development under a plan released by U.S. Interior Secretary Dirk Kempthorne on Wednesday.

The plan identifies 190 million acres — nearly twice the size of California — that would be available for geothermal leasing in 12 Western states. The document, which is expected to be finalized in December, essentially clarifies which public lands are open to geothermal prospecting and which are not.

"Geothermal energy will play a key role in powering America's energy future," Kempthorne said in a news release, "and 90% of our nation's geothermal resources are found on federal land."

Federal spokesmen said the proposal does not open lands previously closed to geothermal development but would speed leasing by laying the groundwork for environmental reviews of individual projects.

California leads the nation in producing geothermal energy and is expected to continue to do so as interest in alternative energy spurs more development. Six long-established fields, including the most productive in the world, are operating on U.S. Bureau of Land Management holdings in Northern California and in Inyo, Mono and Imperial counties.

Of the 190 million acres available for leasing under the Interior proposal, 118 million are managed by the BLM and 79 million by the U.S. Forest Service. All National Park Service lands, as well as wilderness and wilderness study areas and national monuments, would be off limits.

All of Nevada, much of Idaho and Oregon and good chunks of California, Colorado and New Mexico have geothermal potential, based on heat flow maps. Heat from Earth's interior escapes in cracks and fissures in the crust that frequently follow fault networks. The Great Basin, which includes most of Nevada, is slowly pulling itself apart and California is riddled with fault lines, making them hot spots of geothermal production.

Jack G. Peterson, national project manager for the leasing plan, said it is not known how much of the identified acreage will actually yield viable production fields.

In theory, enough energy to supply 12 million homes could eventually be produced under the leasing plan, according to the Interior Department.

Although geothermal facilities have a smaller footprint than solar or wind fields, they would leave their mark on the land much like oil and gas development — with roads, pipelines, power plants and transmission lines.

Daniel Patterson, Southwest director of Public Employees for Environmental Responsibility, said geothermal energy holds potential. "But we still have to consider, are our public lands there to be turned into energy farms? Or should we be investing in rooftop solar?"